feat: Add OpenCode (opencode.ai) client configurator

Add support for the OpenCode CLI client with automatic configuration.

- Create OpenCodeConfigurator implementing IClientConfigurator
- Configure via ~/.config/opencode/opencode.json (XDG standard path)
- Use McpConfigurationHelper for atomic file writes and directory creation
- Support both new config creation and merging with existing config

Co-Authored-By: akshay-kiddopia <[email protected]>
Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: 3 people

MCPForUnity/Editor/Clients/Configurators/OpenCodeConfigurator.cs

@@ -0,0 +1,123 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using MCPForUnity.Editor.Helpers;
+using MCPForUnity.Editor.Models;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace MCPForUnity.Editor.Clients.Configurators
+{
+    /// <summary>
+    /// Configurator for OpenCode (opencode.ai) - a Go-based terminal AI coding assistant.
+    /// OpenCode uses ~/.config/opencode/opencode.json with a custom "mcp" format.
+    /// </summary>
+    public class OpenCodeConfigurator : McpClientConfiguratorBase
+    {
+        private const string ServerName = "unityMCP";
+        private const string SchemaUrl = "https://opencode.ai/config.json";
+
+        public OpenCodeConfigurator() : base(new McpClient
+        {
+            name = "OpenCode",
+            windowsConfigPath = BuildConfigPath(),
+            macConfigPath = BuildConfigPath(),
+            linuxConfigPath = BuildConfigPath()
+        })
+        { }
+
+        private static string BuildConfigPath()
+        {
+            string home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
+            return Path.Combine(home, ".config", "opencode", "opencode.json");
+        }
+
+        public override string GetConfigPath() => CurrentOsPath();
+
+        public override McpStatus CheckStatus(bool attemptAutoRewrite = true)
+        {
+            try
+            {
+                string path = GetConfigPath();
+                if (!File.Exists(path))
+                {
+                    client.SetStatus(McpStatus.NotConfigured);
+                    return client.status;
+                }
+
+                var config = JsonConvert.DeserializeObject<JObject>(File.ReadAllText(path));
+                var unityMcp = config?["mcp"]?[ServerName] as JObject;
+
+                if (unityMcp == null)
+                {
+                    client.SetStatus(McpStatus.NotConfigured);
+                    return client.status;
+                }
+
+                string configuredUrl = unityMcp["url"]?.ToString();
+                string expectedUrl = HttpEndpointUtility.GetMcpRpcUrl();
+
+                if (UrlsEqual(configuredUrl, expectedUrl))
+                {
+                    client.SetStatus(McpStatus.Configured);
+                }
+                else if (attemptAutoRewrite)
+                {
+                    Configure();
+                }
+                else
+                {
+                    client.SetStatus(McpStatus.IncorrectPath);
+                }
+            }
+            catch (Exception ex)
+            {
+                client.SetStatus(McpStatus.Error, ex.Message);
+            }
+
+            return client.status;
+        }
+
+        public override void Configure()
+        {
+            string path = GetConfigPath();
+            McpConfigurationHelper.EnsureConfigDirectoryExists(path);
+
+            JObject config = File.Exists(path)
+                ? JsonConvert.DeserializeObject<JObject>(File.ReadAllText(path)) ?? new JObject()
+                : new JObject { ["$schema"] = SchemaUrl };
+
+            var mcpSection = config["mcp"] as JObject ?? new JObject();
+            config["mcp"] = mcpSection;
+
+            mcpSection[ServerName] = BuildServerEntry();
+
+            McpConfigurationHelper.WriteAtomicFile(path, JsonConvert.SerializeObject(config, Formatting.Indented));
+            client.SetStatus(McpStatus.Configured);
+        }
+
+        public override string GetManualSnippet()
+        {
+            var snippet = new JObject
+            {
+                ["mcp"] = new JObject { [ServerName] = BuildServerEntry() }
+            };
+            return JsonConvert.SerializeObject(snippet, Formatting.Indented);
+        }
+
+        public override IList<string> GetInstallationSteps() => new List<string>
+        {
+            "Install OpenCode (https://opencode.ai)",
+            "Click Configure to add Unity MCP to ~/.config/opencode/opencode.json",
+            "Restart OpenCode",
+            "The Unity MCP server should be detected automatically"
+        };
+
+        private static JObject BuildServerEntry() => new JObject
+        {
+            ["type"] = "remote",
+            ["url"] = HttpEndpointUtility.GetMcpRpcUrl(),
+            ["enabled"] = true
+        };
+    }
+}